This invention relates to silver halide photographic materials and methods of making such materials, and more specifically to photographic materials comprising dispersions of specific phenolic dye-forming photographic coupler combinations with limited amounts of phenolic activators.
Color photographic recording materials generally contain silver halide emulsion layers sensitized to each of the blue, green and red regions of the visible spectrum, with each layer having associated therewith a color forming compound called a coupler. After exposure to light and being subjected to color development with a so-called color developer, the coupling reaction between the oxidation product of an aromatic primary amine and the coupler results in the formation of colored dyes. The blue, green and red sensitive layers yielding respectively, a yellow, magenta and cyan dye.
The coupling speed (hereinafter referred to as coupler activity) in the reaction is preferably desired to be as high as possible so as to obtain higher color density within the limited development time. Higher activity and higher color density are desired to minimize the amount of coupler that is necessary to be coated to obtain this higher color density.
Further, the quality of the resulting dye image is primarily based on the dye hues obtained from the respective color forming coupler compounds. A problem associated with such couplers is that the spectral absorption characteristics of dyes obtained therefrom may not be in the particular narrow wavelength range where absorption is most desired and therefore the coupler may be rejected for commercial use.
As cyan forming couplers capable of satisfying these characteristics for color negative films, phenols have popularly been used, including 2-acylamino-5-alkyl substituted, 2,5-diacylamino substituted, and 2-ureido-5-acylamino substituted phenols. However, the dyes of 2-acylamino substituted phenolic cyan couplers that have an alkyl group with 1 or more carbon atoms in the 5-position typically have an absorption maximum too hypsochromic to be useful for color negative films. The dyes of most 2,5 diacylamino based phenols are also too hypsochromic. While some phenolic couplers which incorporate 2-ureido-5-acylamino functionality are known to advantageously yield high activity, high color density, and suitable dye hue for color negative films, such advantageous couplers are often expensive to manufacture.
Attempts to alter phenolic coupler activities and the absorption characteristics of their respective dyes are usually focused on alterations of the structures of the coupler compounds. This approach, while enjoying some measure of success, is not only time consuming, but also involves the expense of highly focused research programs. Success with such programs is not predictable so that improvements in final coupler activity and final hue values have been elusive, even after concentrated research efforts.
Attempts to shift dye hues of phenolic couplers with addenda and coupler solvents are known (U.S. Pat. No. 5,019,493, U.S. Pat. No. 6,200,741 B1; U.S. Pat. No. 3,676,137; U.S. Pat. No. 4,973,535). The use of accelerators for increasing coupler activity has also been discussed (U.S. Pat. No. 4,774,166) but their use has been mostly associated with the elimination of benzyl alcohol from a color photographic paper processing, not color negative film. The use of non-color developable phenolic compounds as addenda or as organic solvent for 2-ureido-5-acylamino phenolic coupler dispersions has been suggested (U.S. Pat. No. 4,551,422). Such compounds, however, can shift the dye hue lambda max for such couplers to excessively long values for color negative film applications.
It would be desirable to have a cyan coupler dispersion formulation in a color negative photographic element that yields cyan dye of high activity and high density and of the appropriate dye absorption maximum while at the same time allowing for the reduction of expensive 2-ureido-5-acylamino color negative couplers.
The invention provides a color negative photographic element comprising a light sensitive silver halide emulsion imaging layer having associated therewith a cyan dye-forming coupler dispersion comprising a first phenolic cyan dye-forming coupler, a second phenolic cyan dye-forming coupler, a substantially non-color-developable phenolic activator compound, and a non-phenolic organic coupler solvent having a boiling point of at least 150C; wherein
the first phenolic cyan dye-forming coupler is represented by the Formula [P]: 
xe2x80x83where
R1 represents a ballast group,
n is from 0 to 3 and each EW represents independent electron withdrawing groups, and
X represents a hydrogen atom or a coupling off group;
the second phenolic cyan dye-forming coupler is represented by [AP] and comprises at least one of Formula [AP-I] or Formula [AP-II]: 
xe2x80x83where
R2 represents a ballast group,
R3 represents an alkyl group,
R4 represents a hydrogen or halogen atom or an alkyl or an acylamino group, and
Y represents a hydrogen atom or a coupling off group; 
xe2x80x83where
where R5 and R6 each represents an aliphatic group, an aryl group or a heterocyclic group, and
Z represents a hydrogen atom or a group capable of being released upon a coupling reaction with the oxidation product of a developing agent;
the substantially non-color-developable phenolic activator compound is represented by the Formula [ACT]: 
xe2x80x83where
q is from 1 to 3, and each R7 independently represents an aliphatic group, a cycloalkyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylcarbonyl group, an arylcarbonyl group, an acyloxy group, a sulfamoyl group, a sulfonamido group, a sulfonyl group, an aryl group, an alkoxy group, or a halogen atom; and
wherein compounds represented by [P], [AP], and [ACT] are present in the coupler dispersion in relative weight fractions of from 0.30 to 0.65 for [P], from 0.15 to 0.35 for [AP], and from 0.15 to 0.35 for [ACT], provided the sum of the relative weight fractions for [P]+[AP]+[ACT]=1, and the weight ratio of the non-phenolic coupler solvent in the coupler dispersion is from 0.30 to 2.0 relative to the sum of [P]+[AP]+[ACT].
Photographic elements incorporating the dispersion formulation of this invention provide good activity, a cyan dye of high density and acceptable absorption maximum for color negative films. In addition, partial substitution of less expensive cyan auxiliary phenolic coupler [AP] and activator [ACT] for cyan phenolic coupler [P] advantageously allows cost savings.
In accordance with the invention, 2-ureido-5-acylamino substituted phenolic cyan dye-forming couplers are used in combination with generally less expensive phenolic couplers where the 2-substituent is other than an ureido group, along with a substantially non-color-developable phenolic activator compound and a non-phenolic high boiling organic coupler solvent. 2-ureido-5-acylamino substituted phenolic cyan dye-forming couplers which may be employed in accordance with the invention may be represented by the Formula [P]: 
where R1 represents a ballast group, n is from 0 to 3 and each EW represents independent electron withdrawing groups, and X represents a hydrogen atom or a coupling off group.
Electron withdrawing group substituents EW include groups having a Hammett""s sigma para value greater than 0. Hammett""s sigma values may be obtained from xe2x80x9cSubstituent constants for Correlation Analysis in Chemistry and Biologyxe2x80x9d by Hansch and Leo, available from Wiley and Sons, New York, N.Y. (1979). For example the aryl ring may be substituted with a cyano, chloro, fluoro, bromo, iodo, alkyl- or aryl-carbonyl, alkyl- or aryloxycarbonyl, acyloxy, carbonamido, alkyl- or aryl-carbonamido, alkyl- or aryloxycarbonylamino, alkyl- or aryl-sulfonyl, alkyl- or aryl-sulfonyloxy, alkyl- or aryl-oxysulfonyl, alkyl- or aryl- sulfoxide, alkyl- or aryl-sulfamoyl, alkyl- or arylsulfamoylamino, alkyl- or aryl-sulfonamido, aryl, alkyl, alkoxy, aryloxy, nitro, alkyl- or aryl- ureido or alkyl- or aryl-carbamoyl group, any of which may be further substituted. Preferred groups are halogen, cyano, alkoxycarbonyl, alkylsulfamoyl, alkylsulfonamido, alkylsulfonyl, carbamoyl, alkylcarbamoyl or alkylcarbonamindo.
R1 represents a ballast group which controls the migration of the coupler when coated in a photographic layer. Representative ballast groups include substituted or unsubstituted alkyl, aryl, or heterocyclic groups containing 8 to 42 carbon atoms. Representative substituents on such groups include alkyl, aryl, alkoxy, aryloxy, alkylthio, hydroxy, halogen, alkoxycarbonyl, aryloxycarbonyl, carboxy, acyl, acyloxy, amino, anilino, carbonamido (also known as acylamino), carbamoyl, alkylsulfonyl, arylsulfonyl, sulfonamido, and sulfamoyl groups wherein the substituents typically contain 1 to 42 carbon atoms. Such substituents can also be further substituted. Alternatively, the molecule can be made immobile by attachment to a ballast in the form of a polymeric backbone. Preferred ballast groups include xe2x80x94CHRxe2x80x2xe2x80x94O-Aryl, where Rxe2x80x2 represents an alkyl group (preferably 1 to 12 carbon atoms) and Aryl represents an aryl substituent (e.g., phenyl) which may be substituted by, e.g., an alkyl, hydroxy, or alkylsulfonamido group, with branched alkyl group substituents such as t-butyl and t-pentyl being preferred.
Coupling-off groups are groups capable of being released upon a coupling reaction with the oxidation product of a developing agent and are well known in the art. Such groups can modify the reactivity of the coupler and determine the equivalent number of the coupler. Such groups can advantageously affect the layer in which the coupler is coated, or other layers in the photographic recording material, by performing, after release from the coupler, functions such as dye formation, dye hue adjustment, development acceleration or inhibition, bleach acceleration or inhibition, electron transfer facilitation, color correction and the like. Representative classes of such coupling-off groups include, for example, chloro, alkoxy, aryloxy, hetero-oxy, sulfonyloxy, acyloxy, acyl, heterocyclyl, sulfonamido, mercaptotetrazole, benzothiazole, alkylthio (such as mercaptopropionic acid), arylthio, phosphonyloxy and arylazo. These coupling-off groups are described in the art, for example, in U.S. Pat. Nos. 2,455,169; 3,227,551; 3,432,521; 3, 476,563; 3,617,291; 3,880,661; 4,052,212 and 4,134,766; and in U.K. Patents and published Application Nos. 1,466,728; 1,531,927; 1,533,039; 2, 006,755A and 2,017,704A, the disclosures of which are incorporated herein by reference.
Representative couplers of Formula [P] include the following: 
Cyan dye-forming couplers of Formula [P] above are be used in combination with a second cyan dye-forming coupler [AP] represented by either Formula [AP-I]: 
where R2 represents a ballast group; R3 represents an alkyl group (preferably of from 2 to 15 carbon atoms); R4 represents a hydrogen or halogen atom (preferably a chloro atom) or an alkyl or an acylamino group (preferably of from 1 to 15 carbon atoms); and Y represents a hydrogen atom or coupling off group;
or Formula [AP-II]: 
where R5 and R6 each represents an aliphatic group (preferably an aliphatic group having from 1 to 32 carbon atoms, e.g.; methyl, butyl, dodecyl, cyclohexylallyl), an aryl group (e.g., phenyl, naphthyl) or a heterocyclic group (e.g., 2-pyridyl, 2-imidazolyl, 2-furyl, 6-quinolyl), at least one of which is a ballast group.
It is understood throughout this specification that any reference to a substituent by the identification of a group containing a substitutable hydrogen, unless otherwise specifically stated, shall encompass not only the substituent""s unsubstituted form, but also its form substituted with any other photographically useful substituents. For example, each such substitutable group can be substituted with one or more photographically acceptable substituents, such as those selected from an alkyl group, an aryl group, a heterocyclic group, an alkoxy group (e.g., methoxy, 2-methoxyethoxy), an aryloxy group (e.g., 2,4-di-tert-amyl phenoxy, 2-chlorophenoxy, 4-cyanophenoxy), an alkenyloxy group (e.g., 2-propenyloxy), an acyl group (e.g., acetyl, benzoyl), an ester group (e.g., butoxycarbonyl, phenoxycarbonyl, acetoxy, benzoyloxy, butoxysulfonyl, toluenesulfonyloxy), an amido group (e.g., acetylamino, methanesulfonylamino, dipropylsulfamoylamino), a carbamoyl group (e.g., dimethylcarbamoyl, ethylcarbamoyl), a sulfamoyl group (e.g., butylsulfamoyl), an imido group (e.g., succinimido, hydantoinyl), a ureido group (e.g., phenylureido, dimethylureido), an aliphatic or aromatic sulfonyl group (e.g., methanesulfonyl, phenylsulfonyl), an aliphatic or aromatic thio group (e.g., ethylthio, phenylthio), a hydroxy group, a cyano group, a carboxy group, a nitro group, a sulfo group, and a halogen atom. Usually the substituent will have less than 30 carbon atoms and typically less than 20 carbon atoms.
Representative couplers of Formula [AP-I] and [AP-II] include the following: 
Further in combination with the cyan dye forming couplers of Formula [P] and either [AP-I] or [AP-II], a substantially non-color-developable phenolic activator compound represented by the Formula [ACT] is used in accordance with the invention: 
where q is from 1 to 3 and each R7 independently represents an aliphatic group, a cycloalkyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylcarbonyl group, an arylcarbonyl group, an acyloxy group, a sulfamoyl group, a sulfonamido group, a sulfonyl group, an aryl group, an alkoxy group, or a halogen atom. The term xe2x80x9csubstantially non-color-developablexe2x80x9d in connection with the phenolic activator compound is intended to imply that, such phenolic compounds do not function effectively as dye forming couplers relative to the dye-forming activity of the compounds of formulae [P], [AP-I] and [AP-II]. More specifically, should a silver halide photographic light-sensitive material of this invention be prepared containing phenol cyan couplers of Formula [P] and substantially non-color-developable phenolic activator compounds relating to this invention in the same mole amount respectively in a silver halide emulsion layer of the light-sensitive material, and a KODAK FLEXICOLOR C-41 color developing process is applied to the silver halide photographic light-sensitive material, the color density of the non-color-developable phenolic activator compound should not be higher than one fortieth (1/40) of that of the phenol cyan coupler having Formula [P]. Selection of appropriate R7 substituents to differentiate activator compounds from dye-forming coupler compounds will be apparent to one skilled in the art.
Preferably, R7 substituents are chosen so as to result in a logarithmic octanol-water partition coefficient (log P) of at least 5.0 (more preferably at least 6.0) for the phenolic activator compound, in order to provide diffusion resistivity in coated photographic layers and prevent wandering of the compound from the cyan dye-forming couplers. The octanol-water partition coefficient is a physical property used extensively to describe a chemical""s lipophilic or hydrophobic properties. It is the ratio of a chemical""s concentration in the octanol-phase to its concentration in the aqueous phase of a two-phase system at equilibrium. Since measured values range from  less than 10xe2x88x924 to  greater than 10+8 (at least 12 orders of magnitude), the logarithm (log P) is commonly used to characterize its value. The Log Octanol-Water Partition Coefficient Program KOWWIN(copyright) Version 1.6, which is available from the U.S. Environmental Protection Agency via free internet download from the web-page xe2x80x9cwww.epa.gov/oppt/exposure/docs/episuitedl.htmxe2x80x9d, may be used to estimate the logarithmic octanol-water partition coefficient (log P) of organic compounds. KOWWIN requires only a chemical structure to estimate log P values. Structures are entered into KOWWIN by SMILES (Simplified Molecular Input Line Entry System) notations. The KOWWIN program and estimation methodology were developed at Syracuse Research Corporation. Meylan, W. M. and P. H. Howard, xe2x80x9cAtom/fragment contribution method for estimating octanol-water partition coefficientsxe2x80x9d, J. Pharm. Sci. 84: 83-92 (1995) describes the program methodology.
In Formula [ACT], R7 substituent groups may be, e.g., an alkyl radical such as a straight- or branch-chained one preferably having one to 20 carbon atoms including a methyl radical, an ethyl radical, a t-butyl radical, a t-pentyl radical, a t-octyl radical, an n-nonyl radical, an n-dodecyl radical and the like; an alkenyl radical preferably having two to 20 carbon atoms, including an oleyl radical and the like; an aryl radical preferably including a phenyl radical, or a naphthyl radical; a cycloalkyl radical such as those preferably having five to seven carbon atoms, including a cyclohexyl radical; an alkylcarbonyl radical preferably a straight- or branch-chained one having one to 20 carbon atoms, including an acetyl radical; an arylcarbonyl radical preferably including a benzoyl radical; an alkoxycarbonyl radical such as a straight- or branch-chained alkoxycarbonyl radical preferably having one to 20 carbon atoms, including an acetoxy radical; an aryloxycarbonyl radical preferably including phenoxycarbonyl radical; or a cyano radical. Additional possible R7 substituents, as long as they do not make the activator compound substantially color-developable, include a halogen including preferably chlorine and bromine; a heterocyclic radical preferably including a nitrogen-containing one; an alkoxy radical such as, preferably, a straight- or branch-chained alkoxy radical having one to 20 carbon atoms, including a methoxy radical, an ethoxy radical, a t-butyloxy radical, an n-octyloxy radical, an n-decyloxy radical, and an n-dodecyloxy radical; an aryloxy radical such as a phenoxy radical; a hydroxyl radical; an acyloxy radical such as, preferably, an alkylcarbonyloxy radical including an acetoxy radical, and an arylcarbonyloxy radical including a benzoyloxy radical; a hydroxycarbonyl radical; an alkylthio radical such as, preferably, those having one to 20 carbon atoms; an acyl radical such as, preferably, a straight- or branch-chained alkylcarbonyl radical and an arylcarbonyl radical such as preferably a phenyl carbonyl; an acylamino radical such as, preferably, a straight- or branch-chained alkylcarbamide radical having one to 20 carbon atoms, and a benzenecarbamide radical; a sulfonamide radical such as, preferably, a straight- or branch-chained alkylsulfonamide radical having one to 20 carbon atoms, and a benzenesulfonamide radical; a carbamoyl radical such as, preferably, a straight- or branch-chained alkylaminocarbonyl radical having one to 20 carbon atoms, and a phenylaminocarbonyl radical; a sulfonyl radical including a sulfamoyl radical such as, preferably, a straight- or branch-chained alkylaminosulfonyl radical having one to 20 carbon atoms, and a phenylaminosulfonyl radical; a nitro radical; an alkylsulfonyl radical such as preferably one having 1 to 20 carbon atoms. When the described R7 groups may have a substituent, such substituents are, for example, an alkyl radical having one to ten carbon atoms, such as an ethyl radical, an i-propyl radical, an i-butyl radical, t-butyl radical, t-octyl radical or the like; an aryl radical such as a phenyl radical or a naphthyl radical; a halogen such as fluorine, chlorine, bromine or the like; a cyano radical; a nitro radical; a sulfonamide radical such as an alkylsulfonamide radical including a methanesulfonamide radical, a butanesulfonamide radical and the like, an arylsulfonamide radical including a p-toluenesulfonamide radical, or the like; a sulfamoyl radical such as an alkylsulfamoyl radical including a methylsulfamoyl radical, an arylsulfamoyl radical including a phenylsulfamoyl radical, and the like; a sulfonyl radical such as an alkylsulfonyl radical including a methanesulfonyl radical, an arylsulfonyl radical including a p-toluenesulfonyl radical, a halogenosulfonyl radical including a fluorosulfonyl radical, or the like; a carbamoyl radical such as an alkylcarbamoyl radical including a dimethylcarbamoyl radical, an arylcarbamoyl radical including a phenylcarbamoyl radical, or the like; an oxyearbonyl radical such as an alkyloxycarbonyl radical including an ethoxycarbonyl radical, an aryloxycarbonyl radical including a phenoxycarbonyl radical, or the like; an acyl radical such as an alkylcarbonyl radical including an acetyl radical and the like, an arylcarbonyl radical including a benzoyl radical, or the like; a heterocyclic radical such as a nitrogen- containing one including a pyridyl radical, a pyrazolyl radical and the like; an alkoxy radical; an aryloxy radical; an acyloxy radical; and the like. Substituents R7 may themselves include phenolic groups, in which case the phenolic activator compounds may be composed of two or more phenols in combination.
In preferred embodiments, substituents R7 have at least 7, more preferably from 7 to 40, and most preferably 7 to 32 carbon atoms in total, and at least one R7 substituent group is preferably in the fourth position of the phenol ring (para position). The para R7 substituent further preferably represent a straight- or branch-chained alkyl radical having one to 20 carbon atoms, an alkylcarbonyl or aryloxycarbonyl radical, or a sulfamoyl radical, including an arylsulfamoyl radical. Non-para R7 substituents preferably are selected from the preferred para-substituents, and additionally from a nitro radical, an alkoxy radical, or a halogen atom. If the total carbon atoms for the R7 substituents are not at least 7, the log P of the phenolic activator compound may be less than 5.0, and the compound may undesirably wander from coated photographic layers. If the total number of carbon atoms for the R7 substituents are too large, it may become difficult to disperse and incorporate the compounds along with the dye-forming couplers into a silver halide emulsion layer.
The substantially non-color-developable phenolic activator compounds may be solid or liquid at ordinary room temperature (i.e., 25 C) and preferably have the boiling points of not lower than 150C at atmospheric pressure. Such compounds may be readily synthesized in a conventional and well-known process as described, for example, in U.S. Pat. No. 2,835, 579. There are also a number of such compounds which are commercially available. Further, representative synthesis examples are provided below. Representative compounds of Formula [ACT] which may be employed in accordance with the invention include the following, where the KOWWIN Log Octanol-Water Partition Coefficient Estimation Program was used to estimate logP for the activators (designated xe2x80x9clog Kowxe2x80x9d). For example ACT1: LogP (SRC Log Kow)=6.31. This denotes a distribution coefficient of approximately 2.0xc3x97106. High logP is a general indicator of low water solubility, and desirably lowered environmental risk.
While non-color-developable phenolic compounds have been employed in the photographic art as coupler solvents themselves, their use as the sole coupler solvent with dye-forming couplers of Formula [P] and/or Formula [AP-I] or [AP-II] results in either lambda max or photographic activity levels undesired for color negative film applications. In accordance with the invention, to provide the desired combination of photographic activity and formed dye hue for color negative film applications while decreasing the level of coupler of Formula [P] needed to obtain such desired performance, the first cyan dye-forming coupler of Formula [P] is used in combination with the second phenolic cyan dye-forming coupler represented by [AP] (which comprises at least one of Formula [AP-I] or Formula [AP-II]), and the phenolic activator compound of Formula [ACT] in a coupler dispersion along with a high-boiling (boiling point of at least 150C) non-phenolic organic coupler solvent, wherein compounds represented by [P], [AP], and [ACT] are present in the coupler dispersion in relative weight fractions of from 0.30 to 0.65 (more preferably 0.50 to 0.60) for [P], from 0.15 to 0.35 (more preferably 0.20 to 0.25) for [AP], and from 0.15 to 0.35 (more preferably 0.20 to 0.25) for [ACT], provided the sum of the relative weight fractions for [P]+[AP]+[ACT]=1, and the weight ratio of the non-phenolic coupler solvent in the coupler dispersion is from 0.30 to 2.0 (more preferably 0.5 to 1.0) relative to the sum of [P]+[AP]+[ACT]. Use of a non-phenolic coupler solvent and the phenolic activator compound in combination with a coupler of Formula [P] and a second dye forming coupler of Formula [AP-I] or [AP-II] within the indicated ranges has been found to provide desired performance with decreased levels of coupler of Formula [P] in color negative film applications.
Representative non-phenolic coupler solvents which may be used in accordance with the invention include phthalic acid alkyl esters such as diundecyl phthalate, dibutyl phthalate, bis-2-ethylhexyl phthalate, and dioctyl phthalate, phosphoric acid esters such as tricresyl phosphate, diphenyl phosphate, tris-2-ethylhexyl phosphate, and tris-3,5,5-trimethylhexyl phosphate, citric acid esters such as tributylcitrate, tributyl acetylcitrate, 2-(2-butoxyethoxy)ethyl acetate, and 1,4-cyclohexyldimethylene bis(2-ethylhexanoate), benzoic acid esters such as octyl benzoate, aliphatic amides such as N,N-diethyl lauramide, N,N-diethyldodecanamide, N,N-dibutyldodecanamide, mono and polyvalent alcohols such as oleyl alcohol and glycerin monooleate, and aliphatic dioic acid alkyl esters such as dibutyl sebacate and other diesters of the formula Rxe2x80x94(CH2)mxe2x80x94Rxe2x80x2 wherein R and Rxe2x80x2 each represent an alkoxycarbonyl group containing not more than 8 carbon atoms and m is an integer of from 1 to 10. Preferred non-phenolic coupler solvents for use in the invention are the phthalic acid alkyl esters and aliphatic dioic acid alkyl esters, which can be used alone or in combination with one another or with other coupler solvents.
Dispersions of cyan image forming couplers for use in the invention can be prepared by dissolving the couplers and phenolic activator compounds in the non-phenolic high boiling solvent, optionally with or without low boiling or partially water soluble auxiliary organic solvents. The resulting liquid organic phase may then be mixed with an aqueous gelatin solution, and the mixture is then passed through a mechanical mixing device suitable for high shear or turbulent mixing generally suitable for preparing photographic emulsified dispersions, such as a colloid mill, homogenizer, microfluidizer, high speed mixer, ultrasonic dispersing apparatus, blade mixer, device in which a liquid stream is pumped at high pressure through an orifice or interaction chamber, Gaulin mill, blender, etc., to form small particles of the organic phase suspended in the aqueous phase. More than one type of device may be used to prepare the dispersions. The auxiliary organic solvent, if present, may then be removed by evaporation, noodle washing, or membrane dialysis. If not removed prior to coating in a photographic element layer, partially water soluble auxiliary organic solvents may diffuse throughout the hydrophilic colloid layers of the element, and be removed during photographic processing. The dispersion particles preferably have an average particle size of less than 2 microns, generally from about 0.02 to 2 microns, more preferably from about 0.02 to 0.5 micron. These methods are described in detail in U.S. Pat. Nos. 2,322,027, 2,787,544, 2,801,170, 2,801,171, 2,949,360, and 3,396,027. Useful coated levels of the dye-forming couplers range from about 0.1 to about 5.00 g/sq m, or more typically from 0.2 to 3.00 g/sq m. Examples of suitable auxiliary solvents which can be used include: ethyl acetate, isopropyl acetate, butyl acetate, ethyl propionate, 2-ethoxyethylacetate, 2-(2-butoxyethoxy) ethyl acetate, triethylcitrate, dimethylformamide, 2-methyl tetrahydrofuran, triethylphosphate, cyclohexanone, butoxyethyl acetate, methyl isobutyl ketone, methyl acetate, 4-methyl-2-pentanol, diethyl carbitol, 1,1,2-trichloroethane, 1,2-dichloropropane, and the like. Preferred auxiliary solvents include ethyl acetate and 2-(2-butoxyethyoxy) ethyl acetate.
The aqueous phase of the coupler dispersions preferably comprise gelatin as a hydrophilic colloid. This may be gelatin or a modified gelatin such as acetylated gelatin, phthalated gelatin, oxidized gelatin, deionized gelatin, etc. Gelatin may be base-processed, such as lime-processed gelatin, or may be acid-processed, such as acid processed ossein gelatin. Other hydrophilic colloids may also be used, such as a water soluble polymer or copolymer including, but not limited to poly(vinyl alcohol), partially hydrolyzed poly(vinylacetate-co-vinyl alcohol), hydroxyethyl cellulose, poly(acrylic acid), poly(1-vinylpyrrolidone), poly(sodium styrene sulfonate), poly(2-acrylamido-2-methane sulfonic acid), polyacrylamide. Copolymers of these polymers with hydrophobic monomers may also be used.
Typically, the cyan dye-forming coupler dispersion is incorporated in a melt and coated as a layer described herein on a support to form part of a photographic element. When the term xe2x80x9cassociatedxe2x80x9d is employed, it signifies that a reactive compound is in or adjacent to a specified layer where, during processing, it is capable of reacting with other components. Most typically, cyan dye-forming coupler dispersions will be dispersed in a red-light sensitive layer of a photographic element.
The photographic elements can be single color elements or multicolor elements. Multicolor elements contain image dye-forming units sensitive to each of the three primary regions of the spectrum. Each unit can comprise a single emulsion layer or multiple emulsion layers sensitive to a given region of the spectrum. The layers of the element, including the layers of the image-forming units, can be arranged in various orders as known in the art. In an alternative format, the emulsions sensitive to each of the three primary regions of the spectrum can be disposed as a single segmented layer.
A typical multicolor photographic element comprises a support bearing a cyan dye image-forming unit comprised of at least one red-sensitive silver halide emulsion layer having associated therewith at least one cyan dye-forming coupler, a magenta dye image-forming unit comprising at least one green-sensitive silver halide emulsion layer having associated therewith at least one magenta dye-forming coupler, and a yellow dye image-forming unit comprising at least one blue-sensitive silver halide emulsion layer having associated therewith at least one yellow dye-forming coupler. The element can contain additional layers, such as filter layers, interlayers, overcoat layers, and subbing layers.
If desired, the photographic element can be used in conjunction with an applied magnetic layer as described in Research Disclosure, November 1992, Item 34390 published by Kenneth Mason Publications, Ltd., Dudley Annex, 12a North Street, Emsworth, Hampshire P010 7DQ, ENGLAND, and as described in Hatsumi Kyoukai Koukai Gihou No. 94-6023, published Mar. 15, 1994, available from the Japanese Patent Office, the contents of which are incorporated herein by reference. When it is desired to employ the inventive materials in a small format film, Research Disclosure, June 1994, Item 36230, provides suitable embodiments.
In the following discussion of suitable materials for use in the emulsions and elements of this invention, reference will be made to Research Disclosure, September 1996, Item 38957, available as described above, which will be identified hereafter by the term xe2x80x9cResearch Disclosurexe2x80x9d. The contents of the Research Disclosure, including the patents and publications referenced therein, are incorporated herein by reference, and the Sections hereafter referred to are Sections of the Research Disclosure.
Suitable silver halide emulsions and their preparation as well as methods of chemical and spectral sensitization are described in Sections I through V. Various additives such as UV dyes, brighteners, antifoggants, stabilizers, light absorbing and scattering materials, and physical property modifying addenda such as hardeners, coating aids, plasticizers, lubricants and matting agents are described, for example, in Sections II and VI through VIII. Color materials are described in Sections X through XIII. Suitable methods for incorporating couplers and dyes, including dispersions in organic solvents, are described in Section X(E). Scan facilitating is described in Section XIV. Supports, exposure, development systems, and processing methods and agents are described in Sections XV to XX. Certain desirable photographic elements and processing steps are described in Research Disclosure, Item 37038, February 1995.
Coupling-off groups are well known in the art. Such groups can determine the chemical equivalency of a coupler, i.e., whether it is a 2-equivalent or a 4-equivalent coupler, or modify the reactivity of the coupler. Such groups can advantageously affect the layer in which the coupler is coated, or other layers in the photographic recording material, by performing, after release from the coupler, functions such as dye formation, dye hue adjustment, development acceleration or inhibition, bleach acceleration or inhibition, electron transfer facilitation, and color correction. The presence of hydrogen at the coupling site provides a 4-equivalent coupler, and the presence of another coupling-off group usually provides a 2-equivalent coupler. Representative classes of such coupling-off groups include, for example, chloro, alkoxy, aryloxy, hetero-oxy, sulfonyloxy, acyloxy, acyl, heterocyclyl such as oxazolidinyl or hydantoinyl, sulfonamido, mercaptotetrazole, benzothiazole, mercaptopropionic acid, phosphonyloxy, arylthio, and arylazo. These coupling-off groups are described in the art, for example, in U.S. Pat. Nos. 2,455,169, 3,227,551, 3,432,521, 3,476,563, 3,617,291, 3,880,661, 4,052,212 and 4,134,766; and in U.K. Patents and published application Nos. 1,466,728, 1,531,927, 1,533,039, 2,006,755A and 2,017,704A, the disclosures of which are incorporated herein by reference.
Image dye-forming couplers may be included in the element in addition to the cyan dye-forming couplers of Formulae [P], [AP-I], and [AP-II] above, such as additional couplers that form cyan dyes upon reaction with oxidized color developing agents which are described in such representative patents and publications as: U.S. Pat. Nos. 2,367,531, 2,423,730, 2,474,293, 2,772,162, 2,895,826, 3,002,836, 3,034,892, 3,041,236, 4,333,999, 4,883,746 and xe2x80x9cFarbkuppler-eine LiteratureUbersicht,xe2x80x9d published in Agfa Mitteilungen, Band III, pp. 156-175 (1961). Preferably such couplers are phenols and naphthols that form cyan dyes on reaction with oxidized color developing agent.
Couplers that form magenta dyes upon reaction with oxidized color developing agent are described in such representative patents and publications as: U.S. Pat. Nos. 2,311,082, 2,343,703, 2,369,489, 2,600,788, 2,908,573, 3,062,653, 3,152,896, 3,519,429, 3,758,309, 4,540,654, and xe2x80x9cFarbkuppler-eine LiteratureUbersicht,xe2x80x9d published in Agfa Mitteilungen, Band III, pp. 126-156 (1961). Preferably such couplers are pyrazolones, pyrazolotriazoles, or pyrazolobenzimidazoles that form magenta dyes upon reaction with oxidized color developing agents.
Couplers that form yellow dyes upon reaction with oxidized and color developing agent are described in such representative patents and publications as: U.S. Pat. Nos. 2,298,443, 2,407,210, 2,875,057, 3,048,194, 3,265,506, 3,447,928, 4,022,620, 4,443,536, and xe2x80x9cFarbkuppler-eine LiteratureUbersicht,xe2x80x9d published in Agfa Mitteilungen, Band III, pp. 112-126 (1961). Such couplers are typically open chain ketomethylene compounds.
Couplers that form colorless products upon reaction with oxidized color developing agent are described in such representative patents as: U.K. Patent No. 861,138; U.S. Pat. Nos. 3,632,345, 3,928,041, 3,958,993 and 3,961,959. Typically such couplers are cyclic carbonyl containing compounds that form colorless products on reaction with an oxidized color developing agent.
Couplers that form black dyes upon reaction with oxidized color developing agent are described in such representative patents as U.S. Pat. Nos. 1,939,231; 2,181,944; 2,333,106; and 4,126,461; German OLS No. 2,644,194 and German OLS No. 2,650,764. Typically, such couplers are resorcinols or m-aminophenols that form black or neutral products on reaction with oxidized color developing agent.
In addition to the foregoing, so-called xe2x80x9cuniversalxe2x80x9d or xe2x80x9cwashoutxe2x80x9d couplers may be employed. These couplers do not contribute to image dye-formation. Thus, for example, a naphthol having an unsubstituted carbamoyl or one substituted with a low molecular weight substituent at the 2- or 3-position may be employed. Couplers of this type are described, for example, in U.S. Pat. Nos. 5,026,628, 5,151,343, and 5,234,800.
It may be useful to use a combination of couplers any of which may contain known ballasts or coupling-off groups such as those described in U.S. Pat. No. 4,301,235; U.S. Pat. No. 4,853,319 and U.S. Pat. No. 4,351,897. The coupler may contain solubilizing groups such as described in U.S. Pat. No. 4,482,629. The coupler may also be used in association with xe2x80x9cwrongxe2x80x9d colored couplers (e.g. to adjust levels of interlayer correction) and, in color negative applications, with masking couplers such as those described in EP 213.490; Japanese Published Application 58-172,647; U.S. Pat. Nos. 2,983,608; 4,070,191; and 4,273,861; German Applications DE 2,706,117 and DE 2,643,965; U.K. Patent 1,530,272; and Japanese Application 58-113935. The masking couplers may be shifted or blocked, if desired.
Typically, couplers are incorporated in a silver halide emulsion layer in a mole ratio to silver of 0.05 to 1.0 and generally 0.1 to 0.5. Usually the couplers are dispersed in a high-boiling organic solvent in a weight ratio of solvent to coupler of 0.1 to 10.0 and typically 0.1 to 2.0, although dispersions using no permanent coupler solvent are sometimes employed.
The invention materials may be used in association with materials that accelerate or otherwise modify the processing steps e.g. of bleaching or fixing to improve the quality of the image. Bleach accelerator releasing couplers such as those described in EP 193,389; EP 301,477; U.S. Pat. No. 4,163,669; U.S. Pat. No. 4,865,956; and U.S. Pat. No. 4,923,784, may be useful. Also contemplated is use of the compositions in association with nucleating agents, development accelerators or their precursors (UK Patent 2,097,140; U.K. Patent 2,131,188); electron transfer agents (U.S. Pat. No. 4,859,578; U.S. Pat. No. 4,912,025); antifogging and anti color-mixing agents such as derivatives of hydroquinones, aminophenols, amines, gallic acid; catechol; ascorbic acid; hydrazides; sulfonamidophenols; and non color-forming couplers.
The invention materials may also be used in combination with filter dye layers comprising colloidal silver sol or yellow, cyan, and/or magenta filter dyes, either as oil-in-water dispersions, latex dispersions or as solid particle dispersions. Additionally, they may be used with xe2x80x9csmearingxe2x80x9d couplers (e.g. as described in U.S. Pat. No. 4,366,237; EP 96,570; U.S. Pat. No. 4,420,556; and U.S. Pat. No. 4,543,323.) Also, the compositions may be blocked or coated in protected form as described, for example, in Japanese Application 61/258,249 or U.S. Pat. No. 5,019,492.
The invention materials may further be used in combination with image-modifying compounds such as xe2x80x9cDeveloper Inhibitor-Releasingxe2x80x9d compounds (DIR""s). DIR""s useful in conjunction with the compositions of the invention are known in the art and examples are described in U.S. Pat. Nos. 3,137,578; 3,148,022; 3,148,062; 3,227,554; 3,384,657; 3,379,529; 3,615,506; 3,617,291; 3,620,746; 3,701,783; 3,733,201; 4,049,455; 4,095,984; 4,126,459; 4,149,886; 4,150,228; 4,211,562; 4,248,962; 4,259,437; 4,362,878; 4,409,323; 4,477,563; 4,782,012; 4,962,018; 4,500,634; 4,579,816; 4,607,004; 4,618,571; 4,678,739; 4,746,600; 4,746,601; 4,791,049; 4,857,447; 4,865,959; 4,880,342; 4,886,736; 4,937,179; 4,946,767; 4,948,716; 4,952,485; 4,956,269; 4,959,299; 4,966,835; 4,985,336 as well as in patent publications GB 1,560,240; GB 2,007,662; GB 2,032,914; GB 2,099,167; DE 2,842,063, DE 2,937,127; DE 3,636,824; DE 3,644,416 as well as the following European Patent Publications: 272,573; 335,319; 336,411; 346, 899; 362, 870; 365,252; 365,346; 373,382; 376,212; 377,463; 378,236; 384,670; 396,486; 401,612; 401,613. Such compounds are also disclosed in xe2x80x9cDeveloper-Inhibitor-Releasing (DIR) Couplers for Color Photography,xe2x80x9d C. R. Barr, J. R. Thirtle and P. W. Vittum in Photographic Science and Engineering, Vol. 13, p. 174 (1969), incorporated herein by reference. Generally, the developer inhibitor-releasing (DIR) couplers include a coupler moiety and an inhibitor coupling-off moiety (IN). The inhibitor-releasing couplers may be of the time-delayed type (DIAR couplers) which also include a timing moiety or chemical switch which produces a delayed release of inhibitor. Examples of typical inhibitor moieties are: oxazoles, thiazoles, diazoles, triazoles, oxadiazoles, thiadiazoles, oxathiazoles, thiatriazoles, benzotriazoles, tetrazoles, benzimidazoles, indazoles, isoindazoles, mercaptotetrazoles, selenotetrazoles, mercaptobenzothiazoles, selenobenzothiazoles, mercaptobenzoxazoles, selenobenzoxazoles, mercaptobenzimidazoles, selenobenzimidazoles, benzodiazoles, mercaptooxazoles, mercaptothiadiazoles, mercaptothiazoles, mercaptotriazoles, mercaptooxadiazoles, mercaptodiazoles, mercaptooxathiazoles, telleurotetrazoles or benzisodiazoles. In a preferred embodiment, the inhibitor moiety or group is selected from the following formulas: 
wherein RI is selected from the group consisting of straight and branched alkyls of from 1 to about 8 carbon atoms, benzyl, phenyl, and alkoxy groups and such groups containing none, one or more than one such substituent; RII is selected from RI and xe2x80x94SRI; RIII is a straight or branched alkyl group of from 1 to about 5 carbon atoms and m is from 1 to 3; and RIV is selected from the group consisting of hydrogen, halogens and alkoxy, phenyl and carbonamido groups, xe2x80x94COORV and xe2x80x94NHCOORV wherein RV is selected from substituted and unsubstituted alkyl and aryl groups.
Although it is typical that the coupler moiety included in the developer inhibitor-releasing coupler forms an image dye corresponding to the layer in which it is located, it may also form a different color as one associated with a different film layer. It may also be useful that the coupler moiety included in the developer inhibitor-releasing coupler forms colorless products and/or products that wash out of the photographic material during processing (so-called xe2x80x9cuniversalxe2x80x9d couplers).
A compound such as a coupler may release a photographically useful group (xe2x80x9cPUGxe2x80x9d) directly upon reaction of the compound during processing, or indirectly through a timing or linking group. A timing group produces the time-delayed release of the PUG such as groups using an intramolecular nucleophilic substitution reaction (U.S. Pat. No. 4,248,962); groups utilizing an electron transfer reaction along a conjugated system (U.S. Pat. Nos. 4,409,323; 4,421,845; 4,861,701, Japanese Applications 57-188035; 58-98728; 58-209736; 58-209738); groups that function as a coupler or reducing agent after the coupler reaction (U.S. Pat. No. 4,438,193; U.S. Pat. No. 4,618,571) and groups that combine the features describe above. It is typical that the timing group is of one of the formulas: 
wherein IN is the inhibitor moiety, RVII is selected from the group consisting of nitro, cyano, alkylsulfonyl; sulfamoyl; and sulfonamido groups; a is 0 or 1; and RVI is selected from the group consisting of substituted and unsubstituted alkyl and phenyl groups. The oxygen atom of each timing group is bonded to the coupling-off position of the respective coupler moiety of the DIAR.
The timing or linking groups may also function by electron transfer down an unconjugated chain. Linking groups are known in the art under various names. Often they have been referred to as groups capable of utilizing a hemiacetal or iminoketal cleavage reaction or as groups capable of utilizing a cleavage reaction due to ester hydrolysis such as U.S. Pat. No. 4,546,073. This electron transfer down an unconjugated chain typically results in a relatively fast decomposition and the production of carbon dioxide, formaldehyde, or other low molecular weight by-products. The groups are exemplified in EP 464,612, EP 523,451, U.S. Pat. No. 4,146,396, Japanese Kokai 60-249148 and 60-249149.
Suitable developer inhibitor-releasing couplers for use in the present invention include, but are not limited to, the following: 
Especially useful in this invention are tabular grain silver halide emulsions. Tabular grains are those having two parallel major crystal faces and having an aspect ratio of at least 2. The term xe2x80x9caspect ratioxe2x80x9d is the ratio of the equivalent circular diameter (ECD) of a grain major face divided by its thickness (t). Tabular grain emulsions are those in which the tabular grains account for at least 50 percent (preferably at least 70 percent and optimally at least 90 percent) of the total grain projected area. Preferred tabular grain emulsions are those in which the average thickness of the tabular grains is less than 0.3 micrometer (preferably thinxe2x80x94that is, less than 0.2 micrometer and most preferably ultrathinxe2x80x94that is, less than 0.07 micrometer). The major faces of the tabular grains can lie in either {111} or {100} crystal planes. The mean ECD of tabular grain emulsions rarely exceeds 10 micrometers and more typically is less than 5 micrometers.
In their most widely used form tabular grain emulsions are high bromide {111} tabular grain emulsions. Such emulsions are illustrated by Kofron et al U.S. Pat. No. 4,439,520, Wilgus et al U.S. Pat. No. 4,434,226, Solberg et al U.S. Pat. No. 4,433,048, Maskasky U.S. Pat. Nos. 4,435,501, 4,463,087 and 4,173,320, Daubendiek et al U.S. Pat. Nos. 4,414,310 and 4,914,014, Sowinski et al U.S. Pat. No. 4,656,122, Piggin et al U.S. Pat. Nos. 5,061,616 and 5,061,609, Tsaur et al U.S. Pat. Nos. 5,147,771, ""772, ""773, 5,171,659 and 5,252,453, Black et al 5,219,720 and 5,334,495, Delton U.S. Pat. Nos. 5,310,644, 5,372,927 and 5,460,934, Wen U.S. Pat. No. 5,470,698, Fenton et al U.S. Pat. No. 5,476,760, Eshelman et al U.S. Pat. Nos. 5,612,175 and 5,614,359, and Irving et al U.S. Pat. No. 5,667,954.
Ultrathin high bromide {111} tabular grain emulsions are illustrated by Daubendiek et al U.S. Pat. Nos. 4,672,027, 4,693,964, 5,494,789, 5,503,971 and 5,576,168, Antoniades et al U.S. Pat. No. 5,250,403, Olm et al U.S. Pat. No. 5,503,970, Deaton et al U.S. Pat. No. 5,582,965, and Maskasky U.S. Pat. No. 5,667,955.
High bromide {100} tabular grain emulsions are illustrated by Mignot U.S. Pat. Nos. 4,386,156 and 5,386,156.
High chloride {111} tabular grain emulsions are illustrated by Wey U.S. Pat. No. 4,399,215, Wey et al U.S. Pat. No. 4,414,306, Maskasky U.S. Pat. Nos. 4,400,463, 4,713,323, 5,061,617, 5,178,997, 5,183,732, 5,185,239, 5,399,478 and 5,411,852, and Maskasky et al U.S. Pat. Nos. 5,176,992 and 5,178,998. Ultrathin high chloride {111} tabular grain emulsions are illustrated by Maskasky U.S. Pat. Nos. 5,271,858 and 5,389,509.
High chloride {100} tabular grain emulsions are illustrated by Maskasky U.S. Pat. Nos. 5,264,337, 5,292,632, 5,275,930 and 5,399,477, House et al U.S. Pat. No. 5,320,938, Brust et al U.S. Pat. No. 5,314,798, Szajewski et al U.S. Pat. No. 5,356,764, Chang et al U.S. Pat. Nos. 5,413,904 and 5,663,041, Oyamada U.S. Pat. No. 5,593,821, Yamashita et al U.S. Pat. Nos. 5,641,620 and 5,652,088, Saitou et al U.S. Pat. No. 5,652,089, and Oyamada et al U.S. Pat. No. 5,665,530. Ultrathin high chloride {100} tabular grain emulsions can be prepared by nucleation in the presence of iodide, following the teaching of House et al and Chang et al, cited above.
The emulsions can be surface-sensitive emulsions, i.e., emulsions that form latent images primarily on the surfaces of the silver halide grains, or the emulsions can form internal latent images predominantly in the interior of the silver halide grains. The emulsions can be negative-working emulsions, such as surface-sensitive emulsions or unfogged internal latent image-forming emulsions, or direct-positive emulsions of the unfogged, internal latent image-forming type, which are positive-working when development is conducted with uniform-light exposure or in the presence of a nucleating agent. Tabular grain emulsions of the latter type are illustrated by Evans et al. U.S. Pat. No. 4,504,570.
Photographic elements can be exposed to actinic radiation, typically in the visible region of the spectrum, to form a latent image and can then be processed to form a visible dye image. Processing to form a visible dye image includes the step of contacting the element with a color developing agent to reduce developable silver halide and oxidize the color developing agent. Oxidized color developing agent in turn reacts with the coupler to yield a dye.
With negative-working silver halide, the processing step described above provides a negative image. One type of such element, referred to as a color negative film, is designed for image capture. Speed (the sensitivity of the element to low light conditions) is usually critical to obtaining sufficient image in such elements. Such elements are typically silver bromoiodide emulsions coated on a transparent support and are sold packaged with instructions to process in known color negative processes such as the Kodak C-41 process as described in The British Journal of Photography Annual of 1988, pages 191-198. If a color negative film element is to be subsequently employed to generate a viewable projection print as for a motion picture, a process such as the Kodak ECN-2 process described in the H-24 Manual available from Eastman Kodak Co. may be employed to provide the color negative image on a transparent support. Color negative development times are typically 3xe2x80x2 15xe2x80x3 or less and desirably 90 or even 60 seconds or less.
The photographic element of the invention can be incorporated into exposure structures intended for repeated use or exposure structures intended for limited use, variously referred to by names such as xe2x80x9csingle use camerasxe2x80x9d, xe2x80x9clens with filmxe2x80x9d, or xe2x80x9cphotosensitive material package unitsxe2x80x9d.
Preferred color developing agents are p-phenylenediamines such as: 4-amino-N,N-diethylaniline hydrochloride; 4-amino-3-methyl-N,N-diethylaniline hydrochloride; 4-amino-3-methyl-N-ethyl-N-(2-methanesulfonamidoethyl)aniline sesquisulfate hydrate; 4-amino-3-methyl-N-ethyl-N-(2-hydroxyethyl)aniline sulfate; 4-amino-3-(2-methanesulfonamidoethyl)-N,N-diethylaniline hydrochloride; and 4-amino-N-ethyl-N-(2-methoxyethyl)-m-toluidine di-p-toluene sulfonic acid. Development is usually followed by the conventional steps of bleaching, fixing, or bleach-fixing, to remove silver or silver halide, washing, and drying.
The entire contents of the patents and other publications cited in this specification are incorporated herein by reference.